Anatomy subcategory
Cardiovascular
Mnemonics for the cardiac cycle, cardiac output, blood pressure and circulatory control.
Entries in Cardiovascular
Alpha-1 vasoconstricts, beta-1 stimulates the heart, beta-2 vasodilates
A memory aid for the cardiovascular actions of each adrenoceptor subtype.
Aortic pressure, systemic vascular resistance, ventricular radius and wall thickness
A memory aid for the factors setting ventricular afterload.
Arteries stiffen, diastolic function declines, and maximum heart rate falls
A memory aid for the normal cardiovascular changes of ageing.
Water retention through V2 receptors and vasoconstriction through V1 receptors
A memory aid for the cardiovascular actions of vasopressin.
Sinoatrial node 60 to 100, atrioventricular junction 40 to 60, ventricle 20 to 40
A memory aid for the intrinsic rates of the cardiac pacemakers.
Chronotropy, inotropy, dromotropy and lusitropy
A mnemonic for the four autonomic actions on cardiac function.
Myogenic and metabolic mechanisms hold flow steady despite changing pressure
A memory aid for the mechanisms keeping organ blood flow constant.
Bainbridge speeds the heart with atrial stretch; Bezold-Jarisch slows it
A memory aid for two cardiac reflexes with opposite effects on heart rate.
Carotid sinus and aortic arch stretch receptors adjust autonomic outflow within seconds
A memory aid for the short-term regulation of blood pressure.
Viscosity rises steeply with haematocrit, so optimal delivery occurs at an intermediate value
A memory aid for how haematocrit affects flow and oxygen delivery.
About 70 per cent in the venous system, 15 per cent arterial, 5 per cent capillary
A memory aid for how blood volume is distributed around the circulation.
Blood pressure
The pressure exerted by circulating blood on arterial walls.
WiLLiaM MaRRoW: left gives W in V1 and M in V6; right gives M in V1 and W in V6
A mnemonic for distinguishing right from left bundle branch block.
Diffusion for gases, bulk flow for water, vesicular transport for large molecules
A memory aid for how substances cross the capillary wall.
All Points Reach Plateau, Restore
A mnemonic for the five phases of the ventricular cardiac action potential.
Both positive is normal; leads pointing away from each other indicate deviation
A memory aid for working out the cardiac axis from leads I and aVF.
Atrial systole, isovolumetric contraction, ejection, isovolumetric relaxation, then filling
A memory aid for the seven phases of the cardiac cycle.
Cardiac muscle is a functional syncytium with a long refractory period and cannot tetanise
A memory aid for the differences between cardiac and skeletal muscle.
Preload, Rate, Stroke volume, Heart contractility
A mnemonic for the four main determinants of cardiac output.
Cardiac output equals heart rate multiplied by stroke volume
A memory aid for calculating cardiac output and its normal values.
Fick principle, indicator dilution, thermodilution, Doppler and pulse contour analysis
A memory aid for the methods of measuring cardiac output.
Absolute refractory period prevents tetany; the relative period allows vulnerable re-excitation
A memory aid for the absolute and relative refractory periods of cardiac muscle.
Equalisation of diastolic pressures with impaired filling and pulsus paradoxus
A memory aid for the haemodynamics of cardiac tamponade.
Pressure work is far more costly in oxygen than volume work
A memory aid for the components of cardiac work.
Immediate tachycardia and hyperventilation, then polycythaemia and pulmonary hypertension
A memory aid for the circulatory adaptations to high altitude.
Cardiac output rises, resistance falls, and flow is redistributed to muscle
A memory aid for the circulatory changes during dynamic exercise.
Raised hydrostatic pressure, low oncotic pressure, increased permeability, lymphatic obstruction
A mnemonic for the mechanisms of oedema formation.
It reflects right atrial pressure, which depends on volume, cardiac function and compliance
A memory aid for what central venous pressure does and does not tell you.
Carbon dioxide is the most powerful cerebral vasodilator
A memory aid for the factors controlling cerebral perfusion.
Peripheral chemoreceptors sense oxygen; central chemoreceptors sense carbon dioxide
A memory aid for the peripheral and central chemoreceptors.
Purkinje fastest, atrioventricular node slowest
A mnemonic for the relative conduction speeds in the heart.
Sympathetic drive and calcium raise it; hypoxia, acidosis and beta blockade lower it
A memory aid for what increases and decreases myocardial contractility.
Local metabolic factors dominate, especially adenosine and hypoxia
A memory aid for what controls coronary blood flow.
Dilating already maximally dilated vessels diverts flow away from ischaemic territory
A memory aid for the mechanism of coronary steal.
Hypertension, bradycardia and irregular respiration
A mnemonic for the triad of raised intracranial pressure.
Arteriovenous anastomoses under sympathetic control dominate skin flow
A memory aid for how skin blood flow is controlled.
Bradycardia, peripheral vasoconstriction and splenic contraction
A memory aid for the cardiovascular response to facial immersion.
II, III and aVF inferior; V1 to V4 anterior; I, aVL, V5 and V6 lateral
A memory aid for which ECG leads look at which part of the heart.
P atrial depolarisation, QRS ventricular depolarisation, T ventricular repolarisation
A memory aid for what each ECG wave and interval represents.
Hypercalcaemia shortens the QT interval; hypocalcaemia prolongs it
A memory aid for the cardiac effects of calcium disturbance.
Hyperkalaemia gives tall T waves and a wide QRS; hypokalaemia gives flat T waves and U waves
A memory aid for the cardiac effects of hyperkalaemia and hypokalaemia.
Three bipolar limb leads forming a triangle around the heart
A memory aid for the arrangement of the limb leads.
Stroke volume divided by end-diastolic volume, normally over 50 per cent
A memory aid for calculating and interpreting ejection fraction.
Nitric oxide and prostacyclin dilate; endothelin and thromboxane constrict
A memory aid for the vasoactive substances released by endothelium.
Calcium entry triggers calcium release from the sarcoplasmic reticulum
A memory aid for how a cardiac action potential produces contraction.
The first breath drops pulmonary resistance and clamping the cord raises systemic resistance
A memory aid for the circulatory changes at birth.
Cardiac output equals oxygen consumption divided by the arteriovenous oxygen difference
A memory aid for calculating cardiac output from oxygen consumption.
The more the ventricle fills, the harder it contracts, within limits
A memory aid for the relationship between ventricular filling and stroke volume.
First degree long PR, second degree some dropped beats, third degree complete dissociation
A memory aid for the degrees of atrioventricular block.
Sympathetic activation, renin-angiotensin activation, and ventricular remodelling
A memory aid for the compensatory mechanisms in heart failure and why they fail.
S1 atrioventricular valves close, S2 semilunar valves close, S3 rapid filling, S4 atrial contraction
A memory aid for what produces each of the four heart sounds.
Anaemia, pregnancy, thyrotoxicosis, sepsis, beriberi, Paget disease and arteriovenous fistula
A mnemonic for the causes of a high output circulation.
Heart rate
The number of heart beats per minute.
Raised cardiac output early, raised systemic vascular resistance later
A memory aid for the mechanisms underlying essential hypertension.
Perfusion falls, then metabolism, then diastolic and systolic function, then ECG changes, then pain
A memory aid for the sequence of events after coronary occlusion.
Jugular venous pressure
A clinical sign used to estimate right atrial pressure.
a, c and v waves with x and y descents
A memory aid for the waves and descents of the jugular venous pulse.
Phase 1 gives systolic pressure and phase 5 gives diastolic
A memory aid for the five phases of the Korotkoff sounds.
Reynolds number over about 2000 predicts turbulence
A memory aid for the difference between laminar and turbulent flow.
Wall stress equals pressure times radius divided by twice the wall thickness
A memory aid for how chamber size and wall thickness affect wall stress.
Left failure causes pulmonary congestion; right failure causes systemic congestion
A memory aid for distinguishing left from right heart failure.
Adenosine, carbon dioxide, hydrogen and potassium ions, and hypoxia
A memory aid for the metabolites that increase local blood flow.
Diastolic pressure plus one third of the pulse pressure
A memory aid for calculating mean arterial pressure.
Systolic murmurs come from stenotic outflow or leaking inflow valves, and diastolic murmurs the reverse
A mnemonic for the causes of systolic and diastolic murmurs.
Heart rate, contractility and wall stress
A memory aid for the determinants of myocardial oxygen consumption.
Stunning follows restored flow; hibernation persists with reduced flow
A memory aid for distinguishing stunned from hibernating myocardium.
Released by stretched myocardium; they oppose the renin-angiotensin system
A memory aid for the actions of atrial and brain natriuretic peptide.
Hypotension with bradycardia and warm peripheries after high spinal cord injury
A memory aid for the distinctive features of neurogenic shock.
Nitric oxide donation causes venodilatation, reducing preload and wall stress
A memory aid for how nitrates relieve angina.
Mean arterial pressure equals cardiac output multiplied by systemic vascular resistance
A memory aid for the relationship between pressure, flow and resistance.
Delivery equals cardiac output multiplied by arterial oxygen content
A memory aid for calculating oxygen delivery to the tissues.
Phase 4 funny current, phase 0 calcium influx, phase 3 potassium efflux
A memory aid for the three phases of the sinoatrial node action potential.
Flow is proportional to the fourth power of the radius
A memory aid for the determinants of flow through a tube.
Cardiac output and volume rise, resistance and blood pressure fall
A memory aid for the circulatory adaptations of pregnancy.
Venous return, venous tone, blood volume, atrial contraction, heart rate and compliance
A memory aid for the factors setting ventricular preload.
The greatest fall occurs across the arterioles
A memory aid for how pressure falls from aorta to vena cava.
Filling, isovolumetric contraction, ejection, isovolumetric relaxation, traced anticlockwise
A memory aid for the four sides of the ventricular pressure-volume loop.
An indirect measure of left atrial pressure, obtained by occluding a pulmonary artery branch
A memory aid for what the wedge pressure measures.
Low pressure, low resistance, high compliance, and it constricts in hypoxia
A memory aid for how the pulmonary circulation differs from the systemic.
Slow rising in aortic stenosis, collapsing in aortic regurgitation
A memory aid for the abnormal arterial pulse waveforms.
Stroke volume divided by arterial compliance
A memory aid for the determinants of pulse pressure.
Low potassium, magnesium and calcium, plus many drugs, prolong the QT interval
A memory aid for the causes of QT prolongation.
Two pathways, unidirectional block and slow conduction
A memory aid for the three conditions needed for a re-entrant arrhythmia.
Renin, angiotensinogen, angiotensin I, ACE, angiotensin II, aldosterone
A memory aid for the steps of the renin-angiotensin-aldosterone cascade.
Baroreflex tachycardia and vasoconstriction, then fluid shift and hormonal retention
A memory aid for the compensatory response to blood loss.
Blood pools in the legs, venous return falls, and the baroreflex compensates
A memory aid for the circulatory adjustments on standing up.
Systolic blood pressure
The arterial pressure during ventricular contraction.
Hypovolaemic, cardiogenic, obstructive and distributive
A memory aid for the four categories of shock and their haemodynamic profiles.
Heart rate rises on inspiration and falls on expiration through varying vagal tone
A memory aid for the mechanism of respiratory sinus arrhythmia.
Sympathetic tone at rest, metabolic vasodilatation during exercise
A memory aid for the control of blood flow to skeletal muscle.
A quarter of cardiac output at rest, arranged largely in series through the portal vein
A memory aid for the features of the gastrointestinal circulation.
Normal splitting widens on inspiration; wide, fixed and reversed splitting are abnormal
A memory aid for the patterns of S2 splitting and their causes.
Elevation suggests transmural injury; depression suggests subendocardial ischaemia
A memory aid for the significance of ST segment shift.
Hydrostatic pressure pushes fluid out, oncotic pressure pulls it back
A memory aid for the forces governing fluid movement across capillaries.
Dynamic exercise is a volume load; static exercise is a pressure load
A memory aid for the different circulatory loads of isometric and isotonic exercise.
Preload, Afterload, Contractility
A mnemonic for the three determinants of stroke volume.
Reflex, orthostatic and cardiac causes, all reducing cerebral perfusion
A memory aid for the cardiovascular causes of transient loss of consciousness.
About one-third systole and two-thirds diastole at rest
A memory aid for how the cardiac cycle divides between systole and diastole.
Intrinsic sinoatrial rate is about 100; resting vagal tone brings it down to about 70
A memory aid for the dominance of parasympathetic tone in the resting heart.
Pressure rise, reduced venous return, release, then overshoot
A memory aid for the four phases of the Valsalva manoeuvre.
Stenosis creates a pressure load; regurgitation creates a volume load
A memory aid for the loading conditions produced by each valve lesion.
Vasopressors squeeze the vessels; inotropes squeeze the heart
A memory aid for classifying vasoactive drugs by their receptor actions.
Sodium blockers, Beta blockers, Potassium blockers, Calcium blockers
A mnemonic for the classes of antiarrhythmic drug.
Mean systemic filling pressure, right atrial pressure and venous resistance
A memory aid for the factors driving blood back to the heart.
Rapid filling, diastasis and atrial systole
A memory aid for the three phases of diastolic filling.
Elastic arteries store energy in systole and release it in diastole
A memory aid for the role of aortic elasticity.